AHMF: Conf 2001: RB Burnet

Gastro-Intestinal Symptoms and Gastric Emptying Studies in Chronic Fatigue Syndrome

R.B.Burnet, B.Chatterton

Endocrine and Metabolic Unit,
Royal Adelaide Hospital,
Adelaide.

Dept. Nuclear Medicine
Royal Adelaide Hospital.

Gastro-intestinal symptoms are particularly common in CFS patients. They have never been properly assessed but after the fatigue and central symptoms they are the commonest group and cause considerable distress.

To determine the frequency and severity a standard questionnaire of gastro-intestinal symptoms previously validated was used. 3 additional questions about the duration and self assessed severity of CFS were added.

They were given to all patients seen and diagnosed with CFS using Fukuda criteria. Additional questionnaires were sent to self diagnosed CFS patients and on the Internet. Non CFS controls were requested.

212 replies were received, 29 were eliminated from the results as alcohol use did not cause an excessive hangover effect, 62 from personal diagnosis. 56 controls were obtained.

86% of CFS and 56% of controls had one or more upper gastro-intestinal symptoms.

The controls had increased oesophageal symptoms of heart burn and acid reflux where as the CFS group had increased gastric symptoms especially bloating after a small meal and abdominal discomfort. Vomiting was not common. The CFS group all had increased large bowel symptoms of faecal urgency, nocturnal diarrhoea, loose consistency of the stools and increased frequency.

29 of the 62 CFS patients with gastric symptoms of fullness and bloating had gastric emptying studies using a double isotope test of liquid and solid. The solid meal consisted of 100g of cooked ground beef containing 1-1.5 mCi of in vivo labelled 99mTc-sulfur colloid-chicken liver, and the liquid meal consisted of 150ml of 10% dextrose in water labelled with 0.75-1.0 mCi of 113mIn-Diethylenetriaminepentaacetic acid. Analysis of solid and liquid emptying expressed as a percentage of the total meal remaining in the stomach vs. time.

8 controls with idiopathic fatigue were also included. The normal ranges previously established were used in this study.

91% of the CFS patients had an abnormal gastric emptying study. 46% had a delay in the oesophageal emptying, 89% had a delay in the liquid phase and 67% had a delay in the solid phase.

The main abnormality was a delay in the liquid phase rather than the solid. This suggests a central rather than a peripheral causation for the gastric delay. Autonomic dysfunction as seen in diabetes tends to case a delay in the solid phase.

Many explanations are given for the gut symptoms but this study indicates the cause is an abnormality in gut motility. The delay in motility may well lead to bacterial overgrowth.